Shroud arrangement for centrifugal governor weights



C. L- CUMMINS, JR

May 6, 1969 SHROUD ARRANGEMENT FOR CENTRIFUGAL GOVERNOR WEIGHTS Sheet Filed Feb. 5, 1966 SHUTTLE PISTON PRESSURE REGULATOR GOVERNOR CONTROLLED VALVE VALVE SHUT-DOWN BLEED COOLIN6 TAN K VALVE INJECTORS DISTRlBUTOR THROTTLE SHAFT INVl-INTOR. CLESSI E. L. CUMMWS JR.

fla far/re s May 6,1969 c. L-CUMMINS, JR 3,442,141

SHROUD ARRANGEMENT FOR CENTRIFUGAL GOVERNOR WEIGHTS Filed Feb. 5, 1966 Sheet 3 of 2 IO L T Z T0 GOVERNOR p59 ROTOR VALVE 5| 0 55 ll 50 r,

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United States Patent 3,442,141 SHROUD ARRANGEMENT FOR CENTRIFUGAL GOVERNOR WEIGHTS Clessie L. Cummins, Jr., Indianapolis, Ind., assignor, by mesne assignments, to Clessie L. Cummins, Sausalito,

Calif.

Filed Feb. 3, 1966, Ser. No. 524,688 Int. Cl. G01p 3/26 US. Cl. 73--521 6 Claims ABSTRACT OF THE DISCLOSURE An improved internal combustion engine fuel control of type having a governor shaft, Weight and carrier mechanism, a stationary housing with a chamber therein within which the governor rotates, and means for moving fuel 15 The present invention relates generally to fuel injection internal combustion engines and more particularly to a shroud arrangement for the fuel control governor weights of such an engine.

7 A number of different types of fuel injection apparatus for diesel engines are known in the art. One type is disclosed in my patent 3,185,140 and utilizes a governor rotor valve which has a pair of pivoting governor weights associated therewith. The axial position of the rotor valve is controlled by a compression spring and also by the weights which move the rotor valve against the urging of 40 the compression spring to control the fuel supply to the diesel engine. In order to provide lubrication to the weights and the rotor valve and associated apparatus, the weights operate immersed in a fuel containing chamber in the apparatus housing. The lubricating fuel is supplied to the chamber through leakage ports or orifices which 4 lead generally from the fuel pump to the chamber. The pressure of the fuel in the chamber may be above or below atmospheric and the fuel may move from the chamber to the tank or vice versa.

It is desirable that the operation of the governor weight 50 and weight carrier assembly in the chamber add as little heat as possible to the fuel in .the chamber. The addition of heat to the fuel by the beating action of the governor assembly in the fuel results in accelerated wear of the o a a entire pump mechanism. Also; the continuousvibratoryforce of the fuel acting on the weights promotes 'more rapid wear of the bushings about which the weights pivot. Consequently one object of the present invention is to provide means for reducing the amount of heat added to the fuel by the operation of the governor weights 60 of the fuel control. A related object of the invention is to provide means for reducing the mechanical wearing rate of certain parts in a fuel control for internal combustion engines.

One commercially available type of fuel injection ap- 65 paratus for a diesel engine is generally the same as above described except that fuel in the chamber is below atmo-- spheric pressure instead of above atmospheric pressure. Also instead of he fuel being pumped into the chamber from the tank and returning to the tank from the chamber, the fuel passes from the fuel tank through the cham-- her prior to reaching the fuel pump. From the fuel pump the fuel moves to the fuel injectors. It is desirable for optimum operation of the engine that as little air as possible be entrained in the fuel prior to its moving into the injectors. (lonsequently a further object of the invention is to provide a means for reducing the amount of air entrained in the metered fuel of an internal combustion engine. Additionally, by limiting the temperature increase, the effects of large changes in fuel viscosity are reduced, thus enabling more accurate fuel metering in the above fuel injection apparatus.

Related objects and advantages will become apparent as the description proceeds.

'One embodiment of the present invention might include in an internal combustion engine fuel control including a governor weight and carrier mechanism, a housing having a chamber therein within which said governor operates, and means for moving fuel through said chamber for the lubrication of said governor, the improvement which comprises: a shroud mounted on said governor carrier and shielding the weights of the governor, said shroud having a rounded external configuration which is circular in cross section eleminating beating of the fuel by projections.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims.

FIGURE 1 is a schematic block diagram showing fuel flow in a representative fuel control incorporating the present invention.

FIGURE 2 is an illustration partially in section and partially schematic of a portion of the fuel control apparatus illustrated in FIGURE 1.

FIGURE 3 is a view similar to FIGURE 2 of an 0 alternative embodiment of the present invention.

FIGURE 4 is an exploded perspective view of certain portions of the structure illustrated in FIGURE 2.

FIGURE is a perspective view of certain portions of the structure illustrated in FIGURE 3.

For the-purposes of promoting an understanding of the principles of the inveniton, reference will now be made to the embodiment illustrated in the drawing and specific language will be used to describe the same. It will nevertheless be understood that :no limitation of the scope of the invention is thereby intend-ed, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring now more particularly to the drawings, FIGS. 1 and 2 illustrate the use of the present invention in the fuel supply system illustrated in my Patent 3,185,140. 'Illrus, in FIG. 1 of the present specification fuel is pumped from a tank 10 through a filter 11 by means of a fuel transfer pump 12. The fuel is pumped through a filter 15 and a shutdown valve 16 to a governor controlled valve 17. A pressure regulator 20 bypasses a portion of the fuel from filter 15 back to the pump 12,

the amount depending upon the pressure of the fuel moving out of the filter 15.

A cooling bleed block numbered 21 represents the chamber 21 in FIG. 2. Referring now more particular- 1y to FIG. 2, the tank 10 and transfer pump 12 are illustrated although the flow diagram of FIG. 1 has been substantially simplified. As shown in both FIG. 1 and FIG. 2, fuel leaves the chamber 21 and moves along a path or conduit 22 back to the tank 10. A dotted line 25 in FIG. 1 represents the housing 25 of FIG. 2. Thus 0 all of the apparatus schematically illustrated in FIG. 1

as being inside of the dotted line numbered 25 is physically mounted within the housing 25 of FIG. 2.

Patented May 6, 1969 Referring again to FIG. 1, a portion of the fuel leaves the governor controlled valve 17 and moves to a shuttle piston 26 to be again returned to the governor control valve 17 as explained in more detail in my above patent. The fuel then leaves the governor control valve 17 and passes to a throttle shaft 27 which is manually controlled externally of the housing 25. The fuel passing through ports (not shown) in the throttle shaft 27 moves to a distributor rotor valve 31 from which it is distributed to various injectors 32. A small amount of leakage leaves the injectors 32 and is returned via conduit 35 to the tank 10. A dotted line 36 represents a fuel line circuit which bypasses the throttle shaft and wlhich is opened by the governor controlled valve at predetermined engine speeds. A dotted line 37 represents a conduit through which fuel flows only when the engine is turning above the governed speed, said last mentioned flow of fuel occurring from the governor controlled valve to the pump. Of course, the reasons for and mechanism causing the above mentioned fuel flow is explained in more detail in my above mentioned .patent.

Referring now more particularly to FIG. 2, the pump 12 is shown as supplying fuel to the governor rotor valve and also fuel to the chamber 21 through the bleed orifice 40. Thus the fuel within the chamber 21 is under a greater pressure than atmospheric pressure and passes back to the tank through a conduit 22. The fuel within the chamber 211 lubricates a contrifugal governor mechanism 41 as well as other apparatus not shown but mounted within the chamber 21. The governor mechanism 41 is driven through a shaft 42 coupled to the fuel pump 12 and journaled in the housing 25. Rigidly mounted to the shaft 42 is a spur gear 45 which meshes with a spur gear 46 formed integrally with a shroud 47 shielding weights 59 of the governor mechanism. The gear 46 and shroud 47 are mounted upon a shaft 50 having a thrust element 51 secured thereto. A shaft 50 is journaled to the housing 25.

A rotor 55 corresponds to the rotor 38 of my above mentioned patent and has secured to it a driver tang 60 and thrust washer 66 secured to it by a spring pin 67. The tang 60 is straddled by arms 61 of the weights 59. -In operation, the rotor 55 is moved rightwardly by the outward swinging of the weights 59 which causes the arms 61 to push against the rotor thrust was-her 66 and also causes the rotor 55 to rotate due to the rotating weight arms 61 straddling the driver tang 60.

As shown in exploded FIG. 4, the weights 50 are pivoted on the shroud 47 by means of pins 68 which extend through bores 62 in the shroud and bores 65 in the weights. It will be noted that the shroud has a rounded external configuration which is circular in cross section. Thus the shroud eliminates any projections extending outwardly of the governor weights and the beating of the fuel as the governor rotates. In the embodiment of FIG. 2, the shroud 47 has a generally cylindrical 4 external configuration which smoothly curves into a radially extending portion 70 adjacent the spur gear 46. The shroud 47 has an elongated groove 71 therein extending perpendicularly of the axis of the gear 46 and receiving the weights 59.

Referring now to FIGS. 3 and 5, there is illustrated an alternative embodiment of the invention which is intended for use with presently available fuel control apparatus such as that manufactured by the Cummins Engine Company, said apparatus known as the Cummins P-T Fuel System. In one alternative of the Cummins system, the fuel is pumped from a tank through a chamber 101 by means of a fuel pump 102 Which is downstream of the chamber 101. The fuel leaves the fuel pump 102 and moves to a governor rotor valve 116. It can be appreciated that the fuel pressure Within the dhamber 101 is less than atmospheric. Any tendency for the operating structure within the chamber 101 to beat or paddle the fuel produces a frothing or air entraining action which is substantially greater by reason of the less than atmospheric pressure by reason of the less than atmospheric pressure within chamber 101.

A shaft 105 is coupled to the fuel pump 102 and corresponds to the shaft 42 of FIG. 2. Further structure illustrated in FIG. 3 includes a spur gear 106 fixed to the shaft 105 and a spur gear 107 mounted to a shaft 110 and meshing with the spur gear 106. Governor weights 111 of FIG. 3 are swingably mounted upon a weight carrier 112 which has a channel shape. The weight carrier 112 is secured to the shaft 110 by means of a head 115 which is integral with the weight carrier 112. A rotor 116 corresponds to the rotor 55 and is rotated by the Weights 111.

The present improvement to the structure of FIG. 3 is to add a shroud 120 as shown in FIG. 3 and in FIG. 5 and to mount the shroud between the weight carrier 112 and the gear 107. The shroud 120 shields the governor weights and carrier of FIG. 3 and prevents them from beating the fuel and producing a frothing action within the chamber 101. The shroud 120 has a rounded external configuration which is circular in cross section and is cylindrical in configuration. The generally cylindrical configuration of the shroud 120 curves into a radially extending wall 121 which has a central aperture 122 therein, said aperture being received upon the shaft 110. To reduce weight of the shroud 120 there are hollowed out portions 125 formed in the shroud by means of cores during casting. The shroud is also provided with a radially extending elongated groove 126 which fits snugly over the weight carrier 112 whereby the shroud is driven by the weight carrier.

The chart set forth below compares the temperature of the fuel leaving the apparatus of FIG. 2 with and without a shroud similar to FIG. 5 and shows the substantial improvement found by actual test.

Gear Pump Fuel Fuel pump housing leaving reservoir (external) I (external) housing inch wide transfer pump gears, throttle open:

Temperature w/o shroud 119 141. 8 154. 4 157. 1 Temperature with shroud 108 124. 7 130. 1 132. 8

Temperature difference 11 17. 1 24. 3 24. 3

ilnchdwide transfer pump gears, throttle 0 use Temperature w/o shroud 115 147. 2 158. 9 161. 6 Temperature with shroud 114 140. 0 146. 3 147. 2

Temperature difference 1 7. 2 12. 6 14. 4

% iluchdwide transfer pump gears, throttle c ose Temperature w/o shroud 109. O 124. 7 133. 1 142. 7 Temperature with shroud 92. 5 105.8 111. 2 113.0

Temperature difierence 16. 5 l8. 9 21.9 29. 7

(In the last test the air temperature of the room was 78 degrees during the test without the shroud and only 70 degrees with the shroud. The ambient temperatures were approximately equal during the other tests. All of the above data is with the temperatures stabilized.)

It can be appreciated from the above descirption that the present invention provides for an improvement to a fuel control system incorporating means for reducing the amount of heat added to the fuel by the operation of the governor mechanism. It can also be appreciated that the fuel control system of the present invention provides means for reducing the amount of air entrained in the fuel of an internal combustion engine, thus improving the operation of the engine.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention and the scope of the claims are also desired to be protected.

The invention claimed is:

1. In an internal combustion engine fuel control including a centrifugal governor, a housing having a chamber therein within which said governor opeartes, and means for moving fuel through said chamber for the lubrication of said governor, the improvement which comprises: a shroud encasing said governor, said shroud having a rounded external configuration which is circular in cross section, eliminating beating of the fuel by projections, a gear having an'axis and formed integrally with and arranged coaxially with said shroud, said gear providing means for driving said governor, said governor including weights which are pivotally mounted on said shroud and within said shroud, and a shaft secured to said gear and shroud and journal mounting said gear and shroud on said housing, said shroud having an elongated groove extending perpendicularly of the axis of said gear and shroud and receiving said weights, said shroud having a generally cylindrical external shape.

2. In an internal combustion engine fuel control including a centrifual governor, a housing having a chamber therein within which said governor operates, and means for moving fuel through said chamber for the lubrication of said governor, the improvemnt which comprises: a shroud encasing said governor, said shroud having a rounded external configuration which is circular in cross section eliminating beating of the fuel by projections, said governor including a shaft journaled for rotation about an axis of said housing, a gear mounted to said shaft and providing means for driving said governor, said governor including a weight carrier extending radially of said axis and fixed to said shaft, said governor including weights which are pivotally mounted on and within said weight carrier, said shroud being received on said shaft between said gear and said weight carrier, said shroud extending over and around said weight carrier and weights, said shroud having a generally cylindrical external shape which curves smoothly into a wall at one end of said cylindrical shape, said wall having a central aperture through which said shaft extends, said shroud having an elongated groove extending perpendicularly of said axis and snugly receiving said Weight carrier.

3. A shroud arrangement for use in an internal combustion engine fuel control comprising an element having a rounded external configuration and an axis, said element being extenrally circular in cross section taken perpendicularly to said axis, said shroud being internally shaped to fit the external surface of a flyball type governor weight carrier and having a generally cylindrical external shape which curves smoothly into a wall at one end of said cylindrical shape, said wall having a central aperture shaft of the governor, said shroud having an enlongated groove extending perpendicularly of said axis and adapted to snugly receive the governor weight carrier.

4. In an internal combustion engine :fuel control having a governor shaft, weight and carrier mechanism, a stationary housing having a chamber therein within which the governor rotates, and means for moving fuel through said chamber for the lubrication of said governor, the improvement comprising a shroud mounted on said governor shaft for rotation therewith and shielding the weights of the governor, said shroud having a cylindrical outer periphery coaxial with said governor shaft to rotate smoothly without heating in said fuel in said chamber and having an interior that is substantially solid around said shaft except for spaces enabling movement of said govt ernor weights,

so that the fuel in said chamber is protected from the beating action of governor weights that would -occur if said shroud were not present.

5. In an internal combustion engine fuel control including a centrifugal governor, a housing having a chamber within which said governor operates, and means for moving fuel through said chamber for the lubrication of said governor, the improvement which comprises:

a shroud encasing said governor and having a generally cylindrical external shape which is circular in cross section to avoid beating of the fuel,

a gear having an axis and arranged eoaxially with said shroud and driving said governor,

said govenror including weights which are pivotally mounted on said shroud and within said shroud, and

said shroud having an elongated groove extending perpendicularly of the axis of said gear and shroud and receiving said weights,

a shaft secured to said gear and shroud and journalrnounting said gear and shroud on said housing.

6. In an internal combustion engine fuel control including a centrifugal governor, a housing having a chamber therein within which said governor operates, and means for moving fuel through said chamber for the lubrication of said governor, the improvement which comprises:

a shroud encasing said governor, said shroud having a generally cylindrical external configuration which is circular in cross section so as not to beat the fuel, with an end wall having a central shaft-receiving aperture said governor including a shaft journaled for rotation about an axis on said housing,

a weight carrier extending radially of said axis and fixed to said shaft, weights which are pivotally monuted on and within said weight carrier, and

a gear mounted to said shaft and driving said governor,

said shroud being received on said shaft between said gear and said weight carrier, and having an elongated groove extending perpendicularly to said axis and snugly receiving said weight carrier.

References Cited UNITED STATES PATENTS 2,264,874 12/1941 Day 73-550 XR 2,660,421 11/ 1953 Sorensen 73-522 2,660,422 11/1953 Parker 73-522 2,661,729 12/ 3 Reiners 123-140 XR 3,073,329 1/ 1963 Kast 73-510 XR FOREIGN PATENTS 11,242 7/1894 Great Britain.

JAMES J. GILL, Primary Examiner.

US. Cl. X.R.

coaxial with said axis and adapted to receive a bearing 7 73-550 "H050 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 +42 1.41 Dated May 6 1959 Inventor(s) Clessie L. Cummins, Jr.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

F Column 1, line 13, insert the before "type"; line 7011 "he" should read the Column 2, line 41, "inveniton" should read invention Column 3, line 28, "contrifugal" should read centrifugal Column 5, line 5, "descirption" should read description line 26, "opeartes" should read operates line 69 "extenrally" should read --externally Column 6, line 32, "govenror" should read governor line 33, "monuted" should read mounted line 54, "monuted" should read mounted SIGNED AND SEALED MAY 261970 (SEAL) Attest:

WILLIAM E. 'SUHUYLER, JR.

Edward M. Fletcher, I Commissioner of Patents Attesting Offic 

